cooked 580 ex

[Chris&jess]

Helped by a Lumeydyne Cycler which has a recycle time of about two seconds, I apparently popped off way too many full power flashes one after the other on my 580 ex and it's now dead.

Question: Is the element burned out and in need of replacement? If more serious, then what? Anyone know?

Chris

[tim]

Send it to Canon to have the flash tube replaced, I read a thread recently that suggested the standard repair fee for a 580 was $125.

[Lithian]

awww, i was expecting pics of a melty 580ex :(

[Chris&jess]

If it's just the flash tube, I can replace it myself. I've done it once before. It was a tedious (and shocking) project, but doable.
I just wanted to verify that it was the flash tube that bit the dust and not something else...

[DDCSD]

It also could be the circuitry in the flash unit. I fried the circuitry in one of my 540EZ's by popping it off too quickly with a battery pack.

http://photography-on-the.net/forum/showthread.php?t=483135&highlight=fried+540ez

[1ruffryder]

how likely is it to burn one of these out? and whats a safe number of rapid flashes?

[DDCSD]

and whats a safe number of rapid flashes?

The last one right before you smell the smoke...

[1ruffryder]

The last one right before you smell the smoke...
lol thats what i was afraid of

[DDCSD]

lol thats what i was afraid of

That was exactly how many pops I got out of mine. :):lol:

[tim]

There are guidelines in the manual.

[GH_ATL_GA]

If it's just the flash tube, I can replace it myself. I've done it once before. It was a tedious (and shocking) project, but doable.
I just wanted to verify that it was the flash tube that bit the dust and not something else...

If you'd like to minimize the risk of shock in the future here's some useful info taken from the 540EZ service manual:


Even after a full power flash discharge, a charge of 70 to 90 volts remains on the main capacitors in the flash circuit. Therefore, always bleed the capacitors before starting any repair.
(1) Set the flash head to the normal position (bounce 0 [degree] position).
(2) Peel off the rubber cover around the bounce lock knob.
(3) [In the figure below] you can see the main capacitor (+) terminal. Short this terminal and the shoe GND terminal with a bleeder resistor.
See the attached photos for the location of the access point to the (+) terminal on a 580EX flash. Note that the voltage still measures 250+ volts more than 16 hours after the flash was shut off & batteries removed. The main cap of the 540EZ is rated at 1300uF/350V & I suspect the 580 uses the same or larger so there's potential for a good wallop from the stored energy in the cap. If possible, before commencing any work fire off a full power flash & immediately switch off the flash to minimize the voltage on the main cap (though if you're digging into the innards it's likely you're doing so because you can't fire the flash...)

Note that it's important that the flash is in the 'normal' firing position as in the photo otherwise access to the (+) terminal is blocked & you can make an incorrect assumption that no voltage is present.

A couple of references where you can find info re safely discharging capacitors:

http://repairfaq.cis.upenn.edu/sam/strbfaq.htm#strbcap (good source for info on strobe & flash electronics in general)

http://repairfaq.ece.drexel.edu/sam/captest.htm#ctsdc

A resistor of low enough resistance to quickly discharge the 1300uF cap, which may be at voltages around 300V, will have to be very high wattage, much more than what you'll likely find at Radio Shack. Higher value resistors can be of lower wattage, of course, but the time required to discharge increases in direct relation to the increase in resistance. Attempting to simply use a wire jumper is an invitation to disaster!

It's always prudent to measure the voltage across a cap before diving in rather than assuming it's been safely discharged after some time period. Again, refer to the above links for guidance.

The voltages present aren't likely to be lethal, but they can be. There is certainly potential for a nasty shock or burn. Most typically the greatest damage is done to equipment due to the reaction one has on receiving a shock. Things tend to go flying... :-)

[vx360]

I dropped my 580ex and broke the bulb. I followed the directions from another forum user who posted a how-to-guide how to order and replace the bulb for $40 instead of having Canon repair it for over $100. Mine works fine now.

http://photography-on-the.net/forum/showthread.php?t=523087

Found how to replace a broken flash foot here as well:

http://www.planetneil.com/tangents/2007/05/31/repairing-the-canon-580ex-hotshoe-foot/

I'd advise you take pictures of every set of screws and dissassembly because the screws look the same but aren't quite.

[Chris&jess]

how likely is it to burn one of these out? and whats a safe number of rapid flashes?
The Lumedyne cycler came with a warning that this could happen. I was totally into the shoot and I just didn't think of it.
We were on a family shoot at the park with three small uncooperative children. I had two identical setups of 580, Cycler, lightstand, PW, and Fong tupperware. I guess I should consider myself lucky that both units didn't go south.
How many rapid fire shots? about 20 in a row at three second intervals. We did about five sets like this. They both worked up to the very end.
Chris

[Chris&jess]

It also could be the circuitry in the flash unit. I fried the circuitry in one of my 540EZ's by popping it off too quickly with a battery pack.

http://photography-on-the.net/forum/showthread.php?t=483135&highlight=fried+540ez
were you able to repair the circuitry?

[Chris&jess]

If you'd like to minimize the risk of shock in the future here's some useful info taken from the 540EZ service manual:

See the attached photos for the location of the access point to the (+) terminal on a 580EX flash. Note that the voltage still measures 250+ volts more than 16 hours after the flash was shut off & batteries removed. The main cap of the 540EZ is rated at 1300uF/350V & I suspect the 580 uses the same or larger so there's potential for a good wallop from the stored energy in the cap. If possible, before commencing any work fire off a full power flash & immediately switch off the flash to minimize the voltage on the main cap (though if you're digging into the innards it's likely you're doing so because you can't fire the flash...)

Note that it's important that the flash is in the 'normal' firing position as in the photo otherwise access to the (+) terminal is blocked & you can make an incorrect assumption that no voltage is present.

A couple of references where you can find info re safely discharging capacitors:

http://repairfaq.cis.upenn.edu/sam/strbfaq.htm#strbcap (good source for info on strobe & flash electronics in general)

http://repairfaq.ece.drexel.edu/sam/captest.htm#ctsdc

A resistor of low enough resistance to quickly discharge the 1300uF cap, which may be at voltages around 300V, will have to be very high wattage, much more than what you'll likely find at Radio Shack. Higher value resistors can be of lower wattage, of course, but the time required to discharge increases in direct relation to the increase in resistance. Attempting to simply use a wire jumper is an invitation to disaster!

It's always prudent to measure the voltage across a cap before diving in rather than assuming it's been safely discharged after some time period. Again, refer to the above links for guidance.

The voltages present aren't likely to be lethal, but they can be. There is certainly potential for a nasty shock or burn. Most typically the greatest damage is done to equipment due to the reaction one has on receiving a shock. Things tend to go flying... :-)

My unit now has a full charge but I have no way to discharge it. Is there another way to discharge outside of purchasing a fancy tester?
Chris

[JackProton]

My unit now has a full charge but I have no way to discharge it. Is there another way to discharge outside of purchasing a fancy tester?
Chris

The fancy tester is there to make sure the cap is fully discharged and is now safe to handle. You can get a cheap meter at Radio Shack or Sears. I've seen them for as little as $10.

[DDCSD]

were you able to repair the circuitry?

Yep, still works to this day!

[Chris&jess]

Thanks guys!
Chris

[GH_ATL_GA]

The fancy tester is there to make sure the cap is fully discharged and is now safe to handle. You can get a cheap meter at Radio Shack or Sears. I've seen them for as little as $10.

Agree 100%. You shouldn't go poking into the circuit w/o some means of verifying the cap has been discharged. As noted, a reliable multimeter can be had at relatively low cost & is a good, virtually essential, investment. Make sure it has a range that can cover the max voltage you expect to measure, in this case 350V DC. It's pretty common to find meters w/ a 1000V DC range.

One possibility is a RS digital multimeter (DMM) for $20:
http://www.radioshack.com/product/index.jsp?productId=2103174&tab=features

The scant info provided doesn't include the DC volt (or any) range capabilities but almost certainly it will handle 350V DC; ask to be certain, however.

Even less expensive is an analog multimeter for $10:
http://www.radioshack.com/product/index.jsp?productId=2999093&tab=features

This meter definitely has the range you need, but my preference, by far, is a digital meter.

Before making a measurement on the cap test the meter's functionality (& verify you have it set to read DC volts) by making a measurement on a 9V battery, AA cell, or some other low level & known DC voltage.

For discharging the cap probably the best choice of what's available at RS is a 470k (470000) ohm 1/2 watt resistor:

http://www.radioshack.com/product/index.jsp?productId=2062336

The power dissipated at 350V will be appx 0.26W, so well within what this resistor can handle. It will take almost an hour, however, to drop the voltage to less than 1% of its initial value. That's too long for a service bench application, but for occasional use waiting an hour should be no problem.

If you happen to find the voltage is above 330V you might consider 2 of the 220k 1/2W resistors ( http://www.radioshack.com/product/index.jsp?productId=2062335 ) in series just for added safety (350V being the max working voltage of these resistors) rather than a single 470k 1/2 W. If you're really impatient & want to do a bit more work you can make use of parallel sets of these resistors, but that's 'left as an exercise for the reader...' ;)

You'll need a means of clipping the leads to the resistor so pick up some insulated clip leads. These need be nothing fancy, just something to hold the resistor securely while protecting your fingers as you put things in place. The greatest difficulty will likely be mainting contact at the cap + terminal since there's no way to clip to that. A paper clip (handled with insulated pliers or clip lead!) can be pushed into the hole but you'll need a means of securing it in place during the course of discharge. It'll just take a bit of ingenuity...& care!

You can monitor the course of the discharge w/ the meter or just check the voltage after the time the cap should be safely discharged, which should be around 50 minutes or a bit more.

Hope this helps.

[lazer-jock]

I'm by no means an electrical engineer here, but why so high on the resistance? My local RS has 1 ohm 10W wirewound resistors on the shelf. Flashes are designed for fast discharge, are they not? I'm not trying to make any recommendations here, but I am curious as to why this would be a bad idea.

[GH_ATL_GA]

I'm by no means an electrical engineer here, but why so high on the resistance? My local RS has 1 ohm 10W wirewound resistors on the shelf. Flashes are designed for fast discharge, are they not? I'm not trying to make any recommendations here, but I am curious as to why this would be a bad idea.

The power dissipated is given by E^2 / R, so for an E of 300V & an R of 1 ohm you're talking kW of power, albeit a very brief, instantaneous surge. If you've worked around electronics much I suspect you've seen someone discharge a cap using a screwdriver blade or pair of pliers, with the usual sparks & sometimes even molten metal flying. A 1 ohm resistor will give you a similar effect.

In operation the flash is dissipating power as heat & light in the Xe tube; it can handle it. When discharging (bleeding) the cap using a resistor the energy is dissipated as heat in the resistor; properly chosen, it can handle it. I recently had occasion to see someone use a 1k 1/2 watt resistor (which he chose in error) discharge a large cap at appx 200V; beautifully colored flame! :D

[SkipD]

The Lumedyne cycler came with a warning that this could happen. I was totally into the shoot and I just didn't think of it.
We were on a family shoot at the park with three small uncooperative children. I had two identical setups of 580, Cycler, lightstand, PW, and Fong tupperware. I guess I should consider myself lucky that both units didn't go south.
How many rapid fire shots? about 20 in a row at three second intervals. We did about five sets like this. They both worked up to the very end.
ChrisPart of your problem was created by using the 'tupperware' diffuser. Outdoors, there is absolutely nothing to reflect the more than 75% of the light from the flash unit that is spread out in directions other than toward the subject. Thus, you are wasting a lot of the light created by the flash unit. Direct flash (or flash that is ALL reflected toward the subject with a different modifier) would probably have required a LOT less energy from the flash. That would have made the batteries last longer (the normal benefit) and would have created a lot less heat (which is what probably killed your flash unit).

My suggestion - trash the Fongware (or anything like it). Instead, use something like a LumiQuest Promax System (http://www.lumiquest.com/lq931.htm) instead. The Promax System can be as effective outdoors as it is indoors, unlike all of the plastic "diffusers". The Promax System also packs into a camera case very easily, as it is all stored in a flat "wallet" type pouch.

By the way - I agree with the instructions to use a resistor for a slower discharge of the capacitor(s) when working on flash units. I've been in the electronics business for several decades.

[SYS]

Part of your problem was created by using the 'tupperware' diffuser. Outdoors, there is absolutely nothing to reflect the more than 75% of the light from the flash unit that is spread out in directions other than toward the subject. Thus, you are wasting a lot of the light created by the flash unit. Direct flash (or flash that is ALL reflected toward the subject with a different modifier) would probably have required a LOT less energy from the flash. That would have made the batteries last longer (the normal benefit) and would have created a lot less heat (which is what probably killed your flash unit).



Good point and a good reminder.